Rob has now defended the unusual moniker during an interview on Ryan Seacrest's KIIS-FM radio show.

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"I told Kim and Kanye this - I'm like, 'Yo, people are always going to talk, whether it's good or bad, and there's always going to be the haters - just do what you guys feel, that's it'," he said. "Everyone's going to say, 'Oh, you're coming up with some weird celebrity crazy name'. You know how it is."

Rob added that the name "sounds cool" and "has a lot of meaning to it", saying: "As long as they're comfortable with it, you can't really tell them what to do."

Rob confirmed that he has met North, though he explained that he has been giving his sister plenty of space.

"When it comes to babies and stuff like that, I like to give the person all their time with their significant other - let them enjoy their moment," he said. "But, I mean, I'm happy the baby's healthy and my sister's healthy and that's all I really can ask for."

Rob explained that he has already settled on a gift for his niece, saying: "I'm actually looking for a giant animal to get North. Not a real animal - a stuffed animal! The baby came a month early, it's so small. It needs to have a big stuffed animal!"

Rob also said that he would like his sister Khloe to have a baby before a "little Rob" was born, though he joked: "There might be a Rob somewhere but I'm not sure - honestly, I have not been checking my emails!"